Hair straightener



FIG. 1 is a perspective view showing my design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines illustrate portions of the hair straightener and form no part of the claimed design. 

CLAIM I claim the ornamental design for a hair straightener, as shown and described. 